We get free propel at work. Ever since I've been drinking it (many months now) I have gotten headaches. I've been trying to figure out what is in it that could be causing them. Today I did some research. Have any of you heard the 'myth' about aspertame? Whether it's true or not, acesulfame, and sucralose are also sweeteners that can be found in Propel. Mystery solved? You be the judge. What have you heard or experienced?